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Biomedical subjects

H Lamparczyk

Publications and source records attributed to H Lamparczyk.

13 recordsLinked to original sources
PubMed1995

High-performance liquid chromatographic and capillary electrophoretic determination of free nicotinic acid in human plasma and separation of its metabolites by capillary electrophoresis.

Two methods are described based on high-performance liquid chromatography and capillary electrophoresis that provide the selective and sensitive determination of nicotinic acid in human plasma. Moreover, the capillary electrophoresis system was used for the separation of nicotinic acid, nicotinamide, nicotinamide N-oxide, N'-methylnicotinamide, 6-hydroxynicontinic acid, nicotinuric acid and barbital (internal standard). The extraction procedure is simple; no gradient elution or derivatization is required. Both methods can be useful for clinical and biomedical investigations.

Chromatography, High Pressure Liquid↗
PubMed1994

Effect of temperature on separation of norgestrel enantiomers by high-performance liquid chromatography.

The influence of mobile phase composition, concentration of beta-cyclodextrin and temperature on the high-performance liquid chromatographic separation of norgestrel was studied. In studies of the effect of temperature on the enantioselectivity of (+/-)-norgestrel, acetonitrile-water (25:75, v/v) modified by the addition of beta-cyclodextrin (14 mM) was applied as the mobile phase. Enantiomers were detected using UV detection at 240 nm. The capacity factors were measured over a wide range of column temperatures from -5 to 70 degrees C.

Chromatography, High Pressure Liquid↗
PubMed1994

Evaluation of chromatographic methods for the determination of nifedipine in human serum.

Gas-liquid chromatography and high-performance liquid chromatography were compared for the identification and determination of nifedipine in biological samples and the elaboration of the optimum liquid-liquid extraction procedure. The determination limits were 2 and 10 ng/ml, respectively, and the detection limits were 1 and 5 ng/ml, respectively. The calibration graphs were linear in the ranges 2-300 and 10-500 ng/ml, respectively. Recoveries based on three different concentrations were 88.7-95.8% and 93.7-104.2%, respectively. Both methods are sensitive, specific and reproducible enough for pharmacokinetic studies and therapeutic drug monitoring.

Chromatography, Gas↗
PubMed1994

Chromatographic studies of the enantiomeric composition of some therapeutic compositions applied in the treatment of liver and kidney diseases.

A gas-liquid chromatographic system with alpha-cyclodextrin in formamide medium (coated on Chromosorb) was used for the separation of enantiomers of alpha-pinene, beta-pinene, limonene and camphene in medicines applied in the therapy of liver and kidney diseases. The drugs under investigation were produced in Poland (Terpichol and Terpinex), in Germany (Rowachol and Rowatinex) and in Slovenia (Uroterp). It was found that, depending on the manufacturer, medicines possessing similar chemical compositions differ considerably from one another regarding the content of enantiomers, mainly those of alpha-pinene.

Bicyclic Monoterpenes↗
PubMed1991

The metabolism of anthracene and 9,10-dimethylanthracene by bacteria isolated from waters.

The metabolism of two polycyclic aromatic hydrocarbons i.e. anthracene and 9,10-dimethylanthracene by Micrococcus sp., Pseudomonas sp. and Bacillus macerans was examined. The above compounds were used as a sole carbon source for their growth. Using the reversed-phase thin layer chromatography techniques a number of anthracene and 9,10-dimethylanthracene metabolites were isolated and their structures identified spectroscopically. These included anthracene and 9,10-dimethylanthracene cis-dihydrodiols, hydroxy-methyl-derivatives and various phenolic compounds. Bacteria metabolise hydrocarbons using the dioxygenase enzyme system, which differs from the mammalian cytochrome P-450 monoxygenase. Hence in addition rat liver microsomal metabolism of the above hydrocarbons was investigated using the same separation techniques.

Animals↗
PubMed1982

Structure-olfactory activity relationship in a group of substituted phenols.

Using phenol as the standard relative olfactory thresholds have been determined for a series of substituted phenols in experiments with 8--10 human subjects. Significant relations have been obtained describing the activity as a square function of the hydrophobicity parameter corrected for ionization. Chromatographic measurement of phenol polarity has been proposed based on retention indices determined on phases of different polarity. The human sense of smell system has been discussed as a model for studies on drug-receptor interactions involving the living organism as a whole.

Chemical Phenomena↗
PubMedDate not supplied

Fluorescence enhancement of two terpenes commonly present in essential oils.

The fluorescence spectra of anethole and eugenol dissolved in methanol-aqueous binary systems with the addition of alpha- and beta-cyclodextrin were studied. Observed enhancement of the fluorescence intensity is possibly due to the higher quantum yield of the cyclodextrin-hydrocarbon inclusion complexes. The measured fluorescence intensities for eugenol and anethole in the presence of alpha- and beta-cyclodextrin were processed using principal component analysis. The results obtained suggest 1:1 and 2:1 complexation, as confirmed by a double reciprocal plot for terpenes complexed to cyclodextrins. In both cases (anethole and eugenol) detection limits were improved after addition of cyclodextrins. This phenomenon can be applied for improvement of direct fluorescence and HPLC-fluorescence assays.

Allylbenzene Derivatives↗